'use strict';

const chalk = require('chalk');
const path = require('path');

class ModuleScopePlugin {
  constructor(appSrc, allowedFiles = []) {
    this.appSrcs = Array.isArray(appSrc) ? appSrc : [appSrc];
    this.allowedFiles = new Set(allowedFiles);
  }

  apply(resolver) {
    const { appSrcs } = this;
    resolver.hooks.file.tapAsync(
      'ModuleScopePlugin',
      (request, contextResolver, callback) => {
        // Unknown issuer, probably webpack internals
        if (!request.context.issuer) {
          return callback();
        }
        if (
          // If this resolves to a node_module, we don't care what happens next
          request.descriptionFileRoot.indexOf('/node_modules/') !== -1 ||
          request.descriptionFileRoot.indexOf('\\node_modules\\') !== -1 ||
          // Make sure this request was manual
          !request.__innerRequest_request
        ) {
          return callback();
        }
        // Resolve the issuer from our appSrc and make sure it's one of our files
        // Maybe an indexOf === 0 would be better?
        if (
          appSrcs.every(appSrc => {
            const relative = path.relative(appSrc, request.context.issuer);
            // If it's not in one of our app src or a subdirectory, not our request!
            return relative.startsWith('../') || relative.startsWith('..\\');
          })
        ) {
          return callback();
        }
        const requestFullPath = path.resolve(
          path.dirname(request.context.issuer),
          request.__innerRequest_request
        );
        if (this.allowedFiles.has(requestFullPath)) {
          return callback();
        }
        // Find path from src to the requested file
        // Error if in a parent directory of all given appSrcs
        if (
          appSrcs.every(appSrc => {
            const requestRelative = path.relative(appSrc, requestFullPath);
            return (
              requestRelative.startsWith('../') ||
              requestRelative.startsWith('..\\')
            );
          })
        ) {
          callback(
            new Error(
              `You attempted to import ${chalk.cyan(
                request.__innerRequest_request
              )} which falls outside of the project ${chalk.cyan(
                'src/'
              )} directory. ` +
                `Relative imports outside of ${chalk.cyan(
                  'src/'
                )} are not supported. ` +
                `You can either move it inside ${chalk.cyan(
                  'src/'
                )}, or add a symlink to it from project's ${chalk.cyan(
                  'node_modules/'
                )}.`
            ),
            request
          );
        } else {
          callback();
        }
    });
  }
}

module.exports = ModuleScopePlugin;